reloading for semi auto question

[ksmith13]

I have been working up a load for two guns. One is a Remington 700 308 with 26" barrel the other is a CMMG SASS. I worked up the load shooting the 700 and arrived at 44 grains of Varget behind a 175 SMK with federal 210m primers in a Federal case. I then shot the round out of the SASS and had 1 pierced primer and 4 that were raised out of 5 shots. I read somewhere that you should not use the federal primers in a semi-auto. Has anyone else heard that? I have shot FGMM out of the gun with great results, but tried some USA Ammo that I bought a year or so ago and had the same primer problems with it. Should I look for a harder primer? If so what do you recommend? I need as much velocity as possible as I am trying to get to 1000yds with both guns. Thanks in advance

 

[Sonic Crack]

Re: reloading for semi auto question

You need to work up a separate load using your SASS. Semi autos are not the same as bolt guns and usually cant handle the pressures that a bolt gun can. If your trying to KIS and have one load for both guns your going to want to use the SASS as the benchmark so to say since the 700 will handle anything the SASS can.
CCI BR2 primers have a harder cup than 210M and may be better suited for the semi auto but its not a must.

 

[former naval person]

Re: reloading for semi auto question

CCI 34 will handle it. It is made for auto work. Sounds like you also have a overly large firing pin hole in your bolt. May be a design on purpose for the semi, but if not, you could get it bushed and have the firing pin fitted to reduce the cratering. It may not be an overpressure situation, but a mechanical fit problem. JMHO

 

[Temp9]

Re: reloading for semi auto question

I use FGMM SR primers in my AR15 right now. At higher pressures, they do tend to flatten out more, but other than that, no problems. I would recommend keeping your primer pockets clean and uniforming them before the first loading, just to make sure the primer is seated below the case head, though.

Also, never assume a hot load is going to work in another rifle. Even if you're taking a load from a semi and using it in a bolt gun. Chamber dimensions can and will cause massive pressure differences with the same load. As an example, my .223 Wylde gas gun will peak at about 55-56k PSI with my current load. In a SAAMI chamber, that same load would produce just short of 70k PSI. If the bullet happens to be jammed, pressure spikes to 82k PSI. I doubt that's safe, even in bolt guns. Bottom line is every rifle needs its own load work up. Don't assume the SASS will max out quicker than the 700. It probably will, but there's no guarantee.